Balance weight and compressor provided with same

Abstract

Provided are: a balance weight that can improve efficiency of compressors; and a compressor provided with the same. A rotary-shaft weight (54) is provided to a rotary shaft that is rotationally driven about an axis (X) to transmit a drive force to a scroll compression mechanism included in a compressor, and comprises a weight part (54b) that is erected in the direction of the axis (X) and that extends in the circumferential direction with respect to the axis (X). An end (54d) of the weight part (54b) in the circumferential direction is formed by a curved line protruding toward the outer side in the circumferential direction on a plane orthogonal to the axis (X).

Description

Technical Field

[0001] The present disclosure relates to a balance weight and a compressor provided with the same.Background Art

[0002] For example, in a scroll compressor that includes a compression mechanism to which a driving force is transmitted from an electric motor via a rotating shaft, an end portion of a balance weight provided on a drive bush (eccentric bush) may include a surface perpendicular to a rotation direction of the rotating shaft (for example, PTL 1).

[0003] In addition, an end portion of a balance weight provided on a rotor of an electric motor may include a surface perpendicular to a rotation direction of a rotating shaft (for example, PTL 2).Citation ListPatent Literature

[0004] [PTL 1] Japanese Unexamined Patent Application Publication No. 2020-2904 [PTL 2] Japanese Unexamined Patent Application Publication No. 2004-270654 Summary of InventionTechnical Problem

[0005] When the drive bush rotates, the end portion of the balance weight receives resistance from oil as the end portion pushes aside the oil accumulated in a drive bush chamber.

[0006] Additionally, in a case where a refrigerant has a high density, when the rotor of the electric motor rotates, the end portion of the balance weight receives resistance from the refrigerant as the end portion pushes aside the refrigerant.

[0007] In any case, when the balance weight rotates, the end portion of the balance weight receives resistance from a surrounding fluid (oil or fluid) as the end portion pushes aside the fluid.

[0008] In this case, power is consumed in order to rotate the balance weight, which may lead to a decrease in efficiency of the compressor.

[0009] The present disclosure has been made in view of such circumstances, and an object of the present disclosure is to provide a balance weight that can improve efficiency of a compressor and a compressor provided with the same.Solution to Problem

[0010] In order to achieve the above-described object, a balance weight of the present disclosure and a compressor provided with the same employ the following means.

[0011] That is, according to one aspect of the present disclosure, there is provided a balance weight provided on a rotating shaft that transmits a driving force to a compression mechanism of a compressor by being rotationally driven around an axis, the balance weight including: a weight portion that is provided upright in a direction of the axis and that extends along a circumferential direction with respect to the axis, in which an end portion of the weight portion in the circumferential direction is formed by a curve that is convex outward in the circumferential direction in a plane orthogonal to the axis.

[0012] In addition, according to one aspect of the present disclosure, there is provided a balance weight provided on a rotor of an electric motor that rotationally drives a rotating shaft which transmits a driving force to a compression mechanism of a compressor around an axis, the balance weight including: a weight portion that is provided upright in a direction of the axis and that extends along a circumferential direction with respect to the axis, in which an end portion of the weight portion in the circumferential direction is formed by a curve that is convex outward in the circumferential direction in a plane orthogonal to the axis.

[0013] Further, according to one aspect of the present disclosure, there is provided a compressor including the above-described balance weight.Advantageous Effects of Invention

[0014] According to the present disclosure, it is possible to improve efficiency of a compressor.Brief Description of Drawings

[0015] Fig. 1 is a sectional view of a compressor according to one embodiment of the present disclosure. Fig. 2 is a plan view of a rotating shaft weight according to Example 1. Fig. 3 is a side view of the rotating shaft weight according to Example 1. Fig. 4 is a front view of the rotating shaft weight according to Example 1. Fig. 5 is a cross-sectional view taken along a plane P1 shown in Figs. 3 and 7. Fig. 6 is a plan view of a rotating shaft weight according to Example 2. Fig. 7 is a side view of the rotating shaft weight according to Example 2. Fig. 8 is a front view of the rotating shaft weight according to Example 2. Fig. 9 is a plan view of a rotating shaft weight according to Example 3. Fig. 10 is a side view of the rotating shaft weight according to Example 3. Fig. 11 is a cross-sectional view taken along a plane P1 shown in Fig. 10. Fig. 12 is a cross-sectional view taken along a plane P2 shown in Fig. 10. Fig. 13 is a plan view of a rotating shaft weight according to Example 3. Fig. 14 is a side view of the rotating shaft weight according to Example 4. Fig. 15 is a cross-sectional view taken along a plane P1 shown in Fig. 14. Fig. 16 is a plan view of a rotating shaft weight according to a modification example. Fig. 17 is a plan view of a rotor weight according to Example 1. Fig. 18 is a side view of the rotor weight according to Example 1. Fig. 19 is a front view of the rotor weight according to Example 1. Fig. 20 is a cross-sectional view taken along a plane P3 shown in Figs. 18 and 23. Fig. 21 is a side view of the rotor weight attached to a rotor. Fig. 22 is a plan view of a rotor weight according to Example 2. Fig. 23 is a side view of the rotor weight according to Example 2. Fig. 24 is a front view of the rotor weight according to Example 2. Fig. 25 is a plan view of a rotor weight according to Example 3. Fig. 26 is a side view of the rotor weight according to Example 3. Fig. 27 is a cross-sectional view taken along a plane P3 shown in Fig. 26. Fig. 28 is a cross-sectional view taken along a plane P4 shown in Fig. 26. Fig. 29 is a plan view of a rotor weight according to Example 4. Fig. 30 is a side view of the rotor weight according to Example 4. Fig. 31 is a cross-sectional view taken along a plane P3 shown in Fig. 30. Fig. 32 is a plan view of a rotor weight according to a modification example. Description of Embodiments

[0016] Hereinafter, a balance weight and a compressor provided with the same according to one embodiment of the present disclosure will be described with reference to the drawings.[Overview of Compressor]

[0017] As shown in Fig. 1, a compressor 1 is used in an air conditioner and compresses a refrigerant Rf, which is, for example, a gas such as carbon dioxide, in two stages. The compressor 1 is fixed to an installation surface FL via a leg portion 3.

[0018] The compressor 1 includes a housing 11, a rotary compression mechanism (low-stage compression mechanism) 12 provided inside the housing 11, a scroll compression mechanism (high-stage compression mechanism) 13, an electric motor 14, and a rotating shaft 15.

[0019] The housing 11 includes a cylindrical main body portion 21, an upper cover portion 22 that closes an opening at an upper part of the main body portion 21, and a lower cover portion 23 that closes an opening at a lower part of the main body portion 21.

[0020] A hermetic space is formed inside the housing 11 defined by the main body portion 21, the upper cover portion 22, and the lower cover portion 23.

[0021] The rotating shaft 15 is provided inside the housing 11 to extend vertically along an axis X. The rotating shaft 15 is a member for transmitting a driving force from the electric motor 14 to the rotary compression mechanism 12 and the scroll compression mechanism 13.

[0022] An upper end (one end) portion of the rotating shaft 15 is rotatably supported by a scroll-side bearing 31. Additionally, a lower end (the other end) portion of the rotating shaft 15 is rotatably supported by two bearings, that is, an upper bearing 32A (rotary-side upper bearing) and a lower bearing 32B (rotary-side lower bearing).

[0023] The electric motor 14 is disposed at a longitudinal center of the rotating shaft 15 and on an outer peripheral side of the rotating shaft 15 and rotates the rotating shaft 15 around the axis X.

[0024] The electric motor 14 includes a rotor 38 that is fixed to the outer peripheral surface of the rotating shaft 15 and a stator 39 that radially faces the rotor 38 with a gap between an outer peripheral surface of the rotor 38 and the stator 39 and that is fixed, for example, by being shrink-fitted to an inner wall of the main body portion 21 of the housing 11.

[0025] The rotor 38 is provided with rotor passages 38a provided at predetermined intervals in the circumferential direction with respect to the axis X. Each of the rotor passages 38a penetrates through the rotor 38 in a vertical direction (a direction of the axis X). The refrigerant Rf discharged from the rotary compression mechanism 12 flows upward through the rotor passages 38a.

[0026] An upper surface and a lower surface of the rotor 38 are provided with rotor weights 37 (balance weights). Each of the rotor weights 37 is fixed by a pin 38c that penetrates through laminated steel plates of the rotor 38 in the direction of the axis X (fastened together). Details of the shape of the rotor weight 37 will be described below.

[0027] An oil separation plate 38b is fixed to an upper surface of the rotor weight 37 installed on an upper part of the rotor 38. The oil separation plate 38b is formed in a disc shape and is disposed to extend in a horizontal direction. The oil separation plate 38b rotates around the axis X together with the rotor 38.

[0028] The electric motor 14 is connected to a power supply via an inverter (not shown) and rotates the rotating shaft 15 with a variable frequency.

[0029] The rotary compression mechanism 12 is provided inside the housing 11 on a lower end side of the rotating shaft 15.

[0030] The rotary compression mechanism 12 is a two-cylinder mechanism in the present embodiment and includes an eccentric shaft portion 41 that is provided on the rotating shaft 15, a rotor 42 that is fixed to the eccentric shaft portion 41 and that rotates eccentrically with respect to the axis X inside a compression chamber C1 as the rotating shaft 15 rotates, and a cylinder 44 inside which the compression chamber C1 is formed.

[0031] The refrigerant Rf is supplied from the outside to the compression chamber C1 formed in the cylinder 44 via an suction pipe 33 and an suction boss 35 (boss portion).

[0032] The refrigerant Rf compressed in the compression chamber C1 is discharged from a rotary discharge pipe 43 to a region below the electric motor 14 in the housing 11 via the upper bearing 32A.

[0033] Two cylinders 44 with a separate plate 45 sandwiched therebetween are fixed (fastened) from below to the upper bearing 32A and the lower bearing 32B by a bolt (not shown).

[0034] An oil pump 49 fixed by a bolt is provided below the cylinder 44.

[0035] The oil pump 49 draws oil from an oil reservoir at a lower part of the housing 11 and guides the oil to a scroll-side bearing 31 side through an oil supply hole 15a that penetrates along the axis X of the rotating shaft 15.

[0036] The scroll compression mechanism 13 is provided inside the housing 11 on an upper end side of the rotating shaft 15.

[0037] The scroll compression mechanism 13 includes a fixed scroll 51 that is fixed to the scroll-side bearing 31 and an orbiting scroll 57 that is disposed below the fixed scroll 51 to face the fixed scroll 51.

[0038] The fixed scroll 51 includes an end plate 52 fixed to an upper surface of the scroll-side bearing 31 and a fixed wrap 53 protruding downward from the end plate 52.

[0039] A discharge hole 52a that penetrates along the direction of the axis X is formed at a central portion of the end plate 52 (in the vicinity of the axis X).

[0040] The orbiting scroll 57 is disposed to be sandwiched between the scroll-side bearing 31 and the fixed scroll 51 in the direction of the axis X.

[0041] The orbiting scroll 57 includes an end plate 58 connected to an eccentric shaft portion 56 of the rotating shaft 15 and an orbiting wrap 59 protruding upward from the end plate 58.

[0042] The end plate 58 is slidably connected to the eccentric shaft portion 56 provided at an upper end of the rotating shaft 15 via a drive bush 55 and performs an orbiting motion with respect to the axis X as the rotating shaft 15 rotates.

[0043] The orbiting wrap 59 meshes with the fixed wrap 53 to form a compression chamber C2 for compressing the refrigerant Rf between the orbiting wrap 59 and the fixed wrap 53.

[0044] A balance weight chamber 63 is formed between a recessed portion formed at the center of the scroll-side bearing 31 and the lower part of the orbiting scroll 57. Oil is accumulated in the balance weight chamber 63.

[0045] In the balance weight chamber 63, a rotating shaft weight 54 (balance weight) rotates together with the rotating shaft 15.

[0046] The rotating shaft weight 54 is shrink-fitted to the drive bush 55 and is inserted into the eccentric shaft portion 56.

[0047] The rotating shaft weight 54 rotates eccentrically with respect to the axis X as the rotating shaft 15 rotates, thereby balancing the rotating shaft 15 and the orbiting scroll 57 that performs an orbiting motion eccentrically with respect to the axis X. Details of the shape of the rotating shaft weight 54 will be described below.

[0048] The refrigerant Rf, which is compressed by the rotary compression mechanism 12 and discharged into the housing 11, is drawn from an outer peripheral side of the scroll compression mechanism 13 into the compression chamber C2 and is compressed toward a central side.

[0049] The compressed refrigerant Rf is discharged to the outside of the housing 11 through a discharge pipe 34 or the like through the discharge hole 52a formed at the fixed scroll 51.

[0050] A cover 48 is provided below the scroll-side bearing 31 to cover the scroll-side bearing 31.

[0051] The cover 48 is formed by sheet metal processing and is formed in a tubular shape with a gradually increasing diameter from the bottom to the top.

[0052] An suction opening 48a is formed at a lower end of the cover 48. That is, the suction opening 48a is an annular region that is open downward and that is formed between the cover 48 and the rotating shaft 15 in the circumferential direction with respect to the axis X.

[0053] The cover 48 partitions a space on an electric motor 14 side of the housing 11 and a space on the scroll-side bearing 31 side, and only the refrigerant Rf drawn in through the suction opening 48a is guided to the scroll compression mechanism 13.

[0054] An oil level tank 60 is provided outside the housing 11 on the lower side of the housing 11.

[0055] The oil level tank 60 is a hollow container and communicates with the interior of the housing 11 through a lower pipe 61 provided at the lower part and a pressure equalization pipe 62 provided at the upper part.

[0056] A socket 65 is provided at the upper part of the oil level tank 60, and a level gauge (not shown) is installed in the socket 65.

[0057] Oil is guided from the oil reservoir inside the housing 11 into the oil level tank 60 through the lower pipe 61, and the oil level height of the oil reservoir can be measured by the level gauge installed in the socket 65.

[0058] An oil return pipe 67 that extends in the vertical direction while being in contact with the inner wall of the housing 11 is provided inside the housing 11. The oil return pipe 67 is provided such that an upper end (one end) is fixed to the scroll-side bearing 31 and a lower end (the other end) is located in the oil reservoir at the lower part of the housing 11, and is designed to return the oil in the balance weight chamber 63 to the oil reservoir at the lower part.[Regarding Balance Weight (Rotating Shaft Weight) Provided on Rotating Shaft]

[0059] As shown in Figs. 2 to 4, the rotating shaft weight 54 fixed to the eccentric shaft portion 56 via the drive bush 55 includes an annular portion 54a and a weight portion 54b.

[0060] The annular portion 54a is an annular-shaped portion, and the drive bush 55 is fitted to a through-hole 54a1 formed on an inner side thereof.

[0061] The drive bush 55 includes a variable orbiting mechanism with respect to the eccentric shaft portion 56.

[0062] The weight portion 54b is a portion that is provided upright in the direction of the axis X from an upper surface of the annular portion 54a, and is integrally formed with the annular portion 54a.

[0063] The weight portion 54b is a portion formed in an arc shape when the rotating shaft weight 54 is viewed in plan view from the direction of the axis X. In the case of Fig. 2, the weight portion 54b has a semicircular shape formed over substantially 180 degrees.

[0064] A width dimension W and a height dimension H of the weight portion 54b are substantially constant, except for end portions 54d.

[0065] The end portions 54d are portions formed at both ends of the weight portion 54b and are shaped to change the width dimension W and / or the height dimension H such that resistance received from the oil accumulated in the balance weight chamber 63 is reduced.

[0066] Hereinafter, the shape of the end portion 54d will be described with reference to a plurality of examples.<Example 1>

[0067] As shown in Figs. 2 to 4, the end portion 54d is a surface (vertical surface 54d1) that is substantially parallel to the axis X when viewed in side view from a direction orthogonal to the axis X, and the height dimension H is substantially constant along the circumferential direction. It should be noted that the term "vertical" in the vertical surface 54d1 does not limit the actual shape or posture.

[0068] In addition, as shown in Fig. 5, the end portion 54d is formed by a curve that is convex outward in the circumferential direction in a plane P1 (refer to Fig. 3) orthogonal to the axis X. Specifically, the end portion 54d is formed solely by a curve, and the curve is an arc with a radius R.

[0069] As a result, the width dimension W of the end portion 54d smoothly changes along the circumferential direction.<Example 2>

[0070] As shown in Figs. 6 to 8, the end portion 54d includes a surface (vertical surface 54d1) that is substantially parallel to the axis X and a surface (inclined surface 54d2) that is inclined with respect to the axis X when viewed in side view from a direction orthogonal to the axis X. It should be noted that the term "vertical" in the vertical surface 54d1 does not limit the actual shape or posture.

[0071] As a result, the height dimension H of the end portion 54d linearly changes (tapers) along the circumferential direction on the inclined surface 54d2.

[0072] It is preferable that an inclination angle θ of the inclined surface 54d2 is 30 degrees or more with respect to the axis X.

[0073] Additionally, the inclined surface 54d2 has a draft angle that is sufficiently larger than the minimum draft angle required for mold releasing, and is distinguished from a simple draft angle.

[0074] As shown in Fig. 5, the end portion 54d is formed by a curve that is convex outward in the circumferential direction in a plane P1 (refer to Fig. 7) orthogonal to the axis X. Specifically, the end portion 54d is formed solely by a curve, and the curve is an arc with a radius R.

[0075] Consequently, the width dimension W of the end portion 54d in the plane P1 smoothly changes along the circumferential direction.

[0076] Here, the plane P1 is a plane (a plane orthogonal to the axis X) passing through the vertical surface 54d1.<Example 3>

[0077] As shown in Figs. 9 and 10, when viewed in side view from a direction orthogonal to the axis X, the end portion 54d includes a surface (vertical surface 54d1) that is substantially parallel to the axis X, a surface (horizontal surface 54d3) that is orthogonal to the axis X, and another surface (vertical surface 54d4) that is substantially parallel to the axis X. It should be noted that the term "vertical" in the vertical surfaces 54d1 and 54d4 and the term "horizontal" in the horizontal surface 54d3 do not limit the actual shapes or postures.

[0078] Consequently, the end portion 54d forms a step when viewed in side view from a direction orthogonal to the axis X. In other words, the height dimension H of the end portion 54d changes in a stepwise manner along the circumferential direction.

[0079] As shown in Figs. 11 and 12, the end portion 54d is formed by a curve that is convex outward in the circumferential direction in the plane P1 and the plane P2 (refer to Fig. 10) orthogonal to the axis X. Specifically, the end portion 54d is formed solely by a curve, and the curve is an arc with a radius R.

[0080] Consequently, the width dimension W of the end portion 54d in the plane P1 and the plane P2 smoothly changes along the circumferential direction. The radii R of the arcs in the plane P1 and the plane P2 may be different from each other.

[0081] Here, the plane P1 is a plane (a plane orthogonal to the axis X) passing through the vertical surface 54d1, and the plane P2 is a plane (a plane orthogonal to the axis X) passing through the vertical surface 54d4.<Example 4>

[0082] As shown in Figs. 13 and 14, the end portion 54d is a surface (vertical surface 54d1) that is substantially parallel to the axis X when viewed in side view from a direction orthogonal to the axis X, and the height dimension H of the end portion 54d is constant along the circumferential direction.

[0083] In addition, as shown in Fig. 15, the end portion 54d is formed by a curve that is convex outward in the circumferential direction in a plane P1 (refer to Fig. 14) orthogonal to the axis X. Specifically, the end portion 54d is formed solely by a curve, the curve is an arc with a radius R, and the center of the semicircle is at a position offset from the center position of the width dimension W.

[0084] As a result, the width dimension W of the end portion 54d smoothly changes along the circumferential direction, and the tip position of the end portion 54d is biased inward or outward in a radial direction.

[0085] In the case of Fig. 15, by biasing the center of the semicircle to an axis X side, the tip position of the end portion 54d is biased inward in the radial direction.<Others>

[0086] The curve of the end portion 54d may be formed by combining a plurality of radii of curvature. In this case, it is preferable that each radius is at least one-fifth of the width dimension W of the rotor weight 37.

[0087] Additionally, as shown in Fig. 16, the end portion 54d that is shaped to reduce resistance need only be provided at least at a front end of the weight portion 54b in a rotation direction.

[0088] However, by also providing the end portion 54d with such a shape at a rear end in the rotation direction, the shape of the weight portion 54b can be made symmetrical. As a result, the position of the center of gravity of the weight portion 54b becomes easier to understand.

[0089] In addition, the weight portion 54b may be provided upright in the direction of the axis X from a lower surface of the annular portion 54a, in addition to or instead of the upper surface of the annular portion 54a.[Regarding Balance Weight (Rotor Weight) Provided on Rotor of Electric Motor]

[0090] As shown in Figs. 17 to 19, each of the rotor weights 37 fixed to the upper surface and the lower surface of the rotor 38 is a member (the weight portion itself) formed in an arc shape when viewed in plan view from the direction of the axis X. In the case of Fig. 17, the rotor weight 37 has a semicircular shape formed over substantially 180 degrees.

[0091] The width dimension W and the height dimension H of the rotor weight 37 are constant, except for end portions 37d.

[0092] The end portions 37d are portions formed at both ends of the rotor weight 37 and are shaped to change the width dimension W and / or the height dimension H such that resistance received from a refrigerant or a lubricant is reduced.

[0093] Hereinafter, the shape of the end portion 37d will be described with reference to a plurality of examples.<Example 1>

[0094] As shown in Figs. 17 to 19, the end portion 37d is a surface (vertical surface 37d1) that is substantially parallel to the axis X when viewed in side view from a direction orthogonal to the axis X, and the height dimension H is substantially constant along the circumferential direction. It should be noted that the term "vertical" in the vertical surface 37d1 does not limit the actual shape or posture.

[0095] In addition, as shown in Fig. 20, the end portion 37d is formed by a curve that is convex outward in the circumferential direction in a plane P3 (refer to Fig. 18) orthogonal to the axis X. Specifically, the end portion 37d is formed solely by a curve, and the curve is an arc with a radius R.

[0096] As a result, the width dimension W of the end portion 37d smoothly changes along the circumferential direction.

[0097] Fig. 21 shows a state in which the rotor weight 37 of Example 1 is fixed to the rotor 38.<Example 2>

[0098] As shown in Figs. 22 to 24, the end portion 37d includes a surface (vertical surface 37d1) that is substantially parallel to the axis X and a surface (inclined surface 37d2) that is inclined with respect to the axis X when viewed in side view from a direction orthogonal to the axis X. It should be noted that the term "vertical" in the vertical surface 37d1 does not limit the actual shape or posture.

[0099] As a result, the height dimension H of the end portion 37d linearly changes (tapers) along the circumferential direction on the inclined surface 37d2.

[0100] It is preferable that an inclination angle θ of the inclined surface 37d2 is 30 degrees or more with respect to the axis X.

[0101] Additionally, the inclined surface 37d2 has a draft angle that is sufficiently larger than the minimum draft angle required for mold releasing, and is distinguished from a simple draft angle.

[0102] As shown in Fig. 20, the end portion 37d is formed by a curve that is convex outward in the circumferential direction in a plane P3 (refer to Fig. 23) orthogonal to the axis X. Specifically, the end portion 37d is formed solely by a curve, and the curve is an arc with a radius R.

[0103] Consequently, the width dimension W of the end portion 37d in the plane P3 smoothly changes along the circumferential direction.

[0104] Here, the plane P3 is a plane (a plane orthogonal to the axis X) passing through the vertical surface 37d1.<Example 3>

[0105] As shown in Figs. 25 and 26, when viewed in side view from a direction orthogonal to the axis X, the end portion 37d includes a portion that is substantially parallel to the axis X, a surface that is orthogonal to the axis X (vertical surface 37d1), a surface that is substantially parallel to the axis X (horizontal surface 37d3), and another surface that is substantially parallel to the axis X (vertical surface 37d4).

[0106] Consequently, the end portion 37d forms a step when viewed in side view from a direction orthogonal to the axis X. In other words, the height dimension H of the end portion 37d changes in a stepwise manner along the circumferential direction.

[0107] As shown in Figs. 27 and 28, the end portion 37d is formed by a curve that is convex outward in the circumferential direction in a plane P3 and a plane P4 (refer to Fig. 25) orthogonal to the axis X. Specifically, the end portion 37d is formed solely by a curve, and the curve is an arc with a radius R.

[0108] Consequently, the width dimension W of the end portion 37d in the plane P3 and the plane P4 smoothly changes along the circumferential direction. The radii R of the arcs in the plane P3 and the plane P4 may be different from each other.

[0109] Here, the plane P3 is a plane (a plane orthogonal to the axis X) passing through the vertical surface 37d1, and the plane P4 is a plane (a plane orthogonal to the axis X) passing through the vertical surface 37d4.<Example 4>

[0110] As shown in Figs. 29 and 30, the end portion 37d is a surface (vertical surface 37d1) that is substantially parallel to the axis X when viewed in side view from a direction orthogonal to the axis X, and the height dimension H of the end portion 37d is constant along the circumferential direction.

[0111] In addition, as shown in Fig. 31, the end portion 37d is formed by a curve that is convex outward in the circumferential direction in a plane P3 (refer to Fig. 30) orthogonal to the axis X. Specifically, the end portion 37d is formed solely by a curve, the curve is an arc with a radius R, and the center of the semicircle is at a position offset from the center position of the width dimension W.

[0112] As a result, the width dimension W of the end portion 37d smoothly changes along the circumferential direction, and the tip position of the end portion 37d is biased inward or outward in a radial direction.

[0113] In the case of Fig. 31, by biasing the center of the semicircle to the axis X side, the tip position of the end portion 37d is biased inward in the radial direction.<Others>

[0114] The curve of the end portion 37d may be formed by combining a plurality of radii of curvature.

[0115] In the case of Fig. 31, an arc with a radius R and an arc with a radius R' smaller than the radius R are combined. In this case, it is preferable that each radius is at least one-fifth of the width dimension W of the rotor weight 37.

[0116] Additionally, as shown in Fig. 32, the end portion 37d that is shaped to reduce resistance need only be provided at least at a front end in the rotation direction.

[0117] However, by also providing the end portion 37d with such a shape at a rear end in the rotation direction, the shape can be made symmetrical. As a result, the position of the center of gravity becomes easier to understand.

[0118] According to the present embodiment, the following effects are exhibited.

[0119] The end portion 54d of the weight portion 54b of the rotating shaft weight 54 is formed by a curve that is convex outward in the circumferential direction in the planes P1 and P2 orthogonal to the axis X. Therefore, when the rotating shaft weight 54 rotates, the portion formed by the curve (that is, the curved surface portion) reduces the resistance that the weight portion 54b receives from the fluid (for example, oil). As a result, the power consumption associated with the rotation of the rotating shaft weight 54 is reduced, thereby improving the efficiency of the compressor 1.

[0120] In addition, the end portion 37d of the rotor weight 37 is formed by a curve that is convex outward in the circumferential direction in the planes P3 and P4 orthogonal to the axis X. Therefore, when the rotor weight 37 rotates, the portion formed by the curve (that is, the curved surface portion) reduces the resistance that the rotor weight 37 receives from the fluid (for example, the refrigerant Rf). As a result, the power consumption associated with the rotation of the rotor weight 37 is reduced, thereby improving the efficiency of the compressor 1.

[0121] Additionally, in a case where the end portions 54d and 37d include the inclined surfaces 54d2 and 37d2 that are inclined by 30 degrees or more with respect to the axis X when viewed in side view from a direction orthogonal to the axis X, the inclined surfaces 54d2 and 37d2 easily push aside the fluid. Consequently, the resistance that the rotating shaft weight 54 or the rotor weight 37 receives from the fluid (for example, the oil or the refrigerant Rf) is reduced. As a result, the efficiency of the compressor 1 can be improved.

[0122] Further, in a case where the end portions 54d and 37d form a step when viewed in side view from a direction orthogonal to the axis X, the step easily pushes aside the fluid. Consequently, the resistance that the rotating shaft weight 54 or the rotor weight 37 receives from the fluid (for example, the oil or the refrigerant Rf) is reduced. As a result, the efficiency of the compressor 1 can be improved.

[0123] In addition, in a case where both the end portions 54d and 37d are formed by a curve, the shape of the rotating shaft weight 54 or the rotor weight 37 is symmetrical, making it easier to understand the position of the center of gravity.

[0124] It goes without saying that the rotating shaft weight 54 and the rotor weight 37 are not limited to the two-stage compression type compressor 1 disclosed in the present embodiment and can be applied to a rotating shaft or a motor rotor provided in a scroll compressor or a rotary compressor.

[0125] The balance weight and the compressor provided with the same according to one embodiment described above are understood, for example, as follows.

[0126] That is, according to a first aspect of the present disclosure, there is provided a balance weight (54) provided on a rotating shaft (15) that transmits a driving force to a compression mechanism (12, 13) of a compressor (1) by being rotationally driven around an axis (X), the balance weight including: a weight portion (54b) that is provided upright in a direction of the axis and that extends along a circumferential direction with respect to the axis, in which an end portion (54d) of the weight portion in the circumferential direction is formed by a curve that is convex outward in the circumferential direction in a plane (P1, P2) orthogonal to the axis.

[0127] With the balance weight according to this aspect, the weight portion that is provided upright in the direction of the axis and that extends along the circumferential direction with respect to the axis is provided, and the end portion of the weight portion in the circumferential direction is formed by a curve that is convex outward in the circumferential direction in the plane orthogonal to the axis. Therefore, when the balance weight rotates, the portion formed by the curve (that is, the curved surface portion) reduces the resistance that the weight portion receives from the fluid (for example, oil).

[0128] As a result, the power consumption associated with the rotation of the balance weight is reduced, thereby improving the efficiency of the compressor.

[0129] Additionally, according to a second aspect of the present disclosure, there is provided a balance weight (37) provided on a rotor (38) of an electric motor (14) that rotationally drives a rotating shaft (15) which transmits a driving force to a compression mechanism (12, 13) of a compressor (1) around an axis (X), the balance weight including: a weight portion (37) that is provided upright in a direction of the axis and that extends along a circumferential direction with respect to the axis, in which an end portion (37d) of the weight portion in the circumferential direction is formed by a curve that is convex outward in the circumferential direction in a plane (P3, P4) orthogonal to the axis.

[0130] With the balance weight according to this aspect, the weight portion that is provided upright in the direction of the axis and that extends along the circumferential direction with respect to the axis is provided, and the end portion of the end surface of the weight portion in the circumferential direction is formed by a curve that is convex outward in the circumferential direction in the plane orthogonal to the axis. Therefore, when the balance weight rotates, the portion formed by the curve (that is, the curved surface portion) reduces the resistance that the weight portion receives from the fluid (for example, the refrigerant). As a result, the power consumption associated with the rotation of the balance weight is reduced, thereby improving the efficiency of the compressor.

[0131] Further, according to a third aspect of the present disclosure, in the balance weight described in the first and second aspects, the end portion of the weight portion includes an inclined surface (54d2, 37d2) that is inclined by 30 degrees or more with respect to the axis when viewed in side view from a direction orthogonal to the axis.

[0132] With the balance weight according to this aspect, the end portion of the end surface of the weight portion includes the inclined surface that is inclined by 30 degrees or more with respect to the axis when viewed in side view from a direction orthogonal to the axis. Therefore, the inclined surface easily pushes aside the fluid. Consequently, the resistance that the weight portion receives from the fluid (for example, the oil or the refrigerant) is reduced. As a result, the efficiency of the compressor can be improved.

[0133] Furthermore, according to a fourth aspect of the present disclosure, in the balance weight described in the first and second aspects, the end portion of the weight portion forms a step when viewed in side view from a direction orthogonal to the axis.

[0134] With the balance weight according to this aspect, the end portion of the end surface of the weight portion forms a step when viewed in side view from a direction orthogonal to the axis. Therefore, the step easily pushes aside the fluid. Consequently, the resistance that the weight portion receives from the fluid (for example, the oil or the refrigerant) is reduced. As a result, the efficiency of the compressor can be improved.

[0135] In addition, according to a fifth aspect of the present disclosure, in the balance weight described in any one of the first to fourth aspects, the curve forming the end portion of the weight portion is an arc, and a center of the arc is offset from a width-wise center of the weight portion.

[0136] With the balance weight according to this aspect, the curve forming the end portion of the weight portion is an arc, and the center of the arc is offset from the width-wise center of the weight portion.

[0137] Additionally, according to a sixth aspect of the present disclosure, in the balance weight described in any one of the first to fifth aspects, both end portions of the weight portion in the circumferential direction are formed by the curve.

[0138] With the balance weight according to this aspect, both end portions of the end surfaces of the weight portion in the circumferential direction are formed by a curve. Therefore, the shape of the weight portion is symmetrical, making it easier to understand the position of the center of gravity.

[0139] Further, according to a seventh aspect of the present disclosure, there is provided a compressor including the balance weight according to any one of the first to sixth aspects.Reference Signs List

[0140] 1: compressor 3: leg portion 11: housing 12: rotary compression mechanism (low-stage compression mechanism) 13: scroll compression mechanism (high-stage compression mechanism) 14: electric motor 15: rotating shaft 15a: oil supply hole 21: main body portion 22: upper cover portion 23: lower cover portion 31: scroll-side bearing 32A: upper bearing (rotary-side upper bearing) 32B: lower bearing (rotary-side lower bearing) 33: suction pipe 34: discharge pipe 35: suction boss (boss portion) 37: rotor weight (balance weight, weight portion) 37d: end portion 37d1: vertical surface 37d2: inclined surface 37d3: horizontal surface 37d4: vertical surface 38: rotor 38a: rotor passage 38b: oil separation plate 38c: pin 39: stator 41: eccentric shaft portion 42: rotor 43: rotary discharge pipe 44: cylinder 45: separate plate 48: cover 48a: suction opening 49: oil pump 51: fixed scroll 52: end plate 52a: discharge hole 53: fixed wrap 54: rotating shaft weight (balance weight) 54a: annular portion 54a1: through-hole 54b: weight portion 54d: end portion 54d1: vertical surface 54d2: inclined surface 54d3: horizontal surface 54d4: vertical surface 55: drive bush 56: eccentric shaft portion 57: orbiting scroll 58: end plate 59: orbiting wrap 60: oil level tank 61: lower pipe 62: pressure equalization pipe 63: balance weight chamber 65: socket C1: compression chamber C2: compression chamber FL: installation surface X: axis

Claims

1. A balance weight provided on a rotating shaft that transmits a driving force to a compression mechanism of a compressor by being rotationally driven around an axis, the balance weight comprising: a weight portion that is provided upright in a direction of the axis and that extends along a circumferential direction with respect to the axis, wherein an end portion of the weight portion in the circumferential direction is formed by a curve that is convex outward in the circumferential direction in a plane orthogonal to the axis.

2. A balance weight provided on a rotor of an electric motor that rotationally drives a rotating shaft which transmits a driving force to a compression mechanism of a compressor around an axis, the balance weight comprising: a weight portion that is provided upright in a direction of the axis and that extends along a circumferential direction with respect to the axis, wherein an end portion of the weight portion in the circumferential direction is formed by a curve that is convex outward in the circumferential direction in a plane orthogonal to the axis.

3. The balance weight according to Claim 1 or 2, wherein the end portion of the weight portion includes an inclined surface that is inclined by 30 degrees or more with respect to the axis when viewed in side view from a direction orthogonal to the axis.

4. The balance weight according to Claim 1 or 2, wherein the end portion of the weight portion forms a step when viewed in side view from a direction orthogonal to the axis.

5. The balance weight according to Claim 1 or 2, wherein the curve forming the end portion of the weight portion is an arc, and a center of the arc is offset from a width-wise center of the weight portion.

6. The balance weight according to Claim 1 or 2, wherein both end portions of the weight portion in the circumferential direction are formed by the curve.

7. A compressor comprising: the balance weight according to Claim 1 or 2.

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